In the prior art, a local backlight adjustment method is often used for the control of a display device such as a liquid crystal display, in order to reduce the power consumption of the display device, enhance the contrast of the displayed image, reduce the image retention, etc. This local backlight adjustment method actually divides the backlight of the display device into multiple backlight sub-regions, and then controls respective backlight sub-regions independently. On this basis, the peak driving technique can be further combined, that is, peak driving is performed for some backlight sub-regions such that these backlight sub-regions reach possible maximum luminance so as to make the details of the displayed image clearer and further enhance the contrast of the displayed image.